The invention relates to a method for determining haemodynamic parameters from patient pressure signals.
For the invasive, intra-arterial and intravenous pressure measurement in cardiology, intensive medicine and anaesthesia transfer systems are used in which the pressure measurement is carried out in the body of a patient and transferred through the transfer system, which is designed for example as a catheter, to a storage medium set away from the patient body.
There is therefore the need to both store and analyse the transferred data. It is particularly of interest to determine from the incoming data haemodynamic parameters from which a doctor can deduce his diagnosis.
There is frequently the problem that the incoming signals originating in the body of the patient are subject to errors (artifacts). Such errors arise in particular in dependence on the length, cross-section, structure and properties of the catheter material. This can lead to resonances, attenuations and energy losses in the detected measured pressure value which ultimately leads to a falsification of the patient signal.
One method for correcting such artifacts which are conditioned through the transfer system, is known from German Patent Application No. DE 198 20 844 A1; one method for determining and monitoring the transfer function of the transfer system is described in German Patent Application No. DE 100 49 734 A1.
However artifacts also often occur which are not conditioned by transfer errors, such as for example motion artifacts which happen through manipulation on the catheter or knocking of the catheter in the vessel or through a break in the pressure measurement when changing the catheter or injection, as well as such artifacts which arise on flushing through the system. The haemodynamic parameters which are calculated from such falsified patient signals can thus not provide the doctor with a suitable foundation on which to base his diagnosis.
The object of the present invention is therefore to provide a method for determining haemodynamic parameters from patient pressure signals in which the determination is only carried out on the basis of suitable signals.